A new test to improve stem cell safety

We have developed the first safety test specifically for human induced pluripotent stem cells.

The challenge

Improving the safety of stem cells

Human induced pluripotent stem cells (iPSC) have the potential to generate healthy cells and tissues for the study and medical treatment of a large number of diseases. Therefore, ensuring the safety and stability of these cells is a priority for scientists around the world.

iPS cells in the lab

iPS cells in the lab

Our response

A new test that identifies unsafe cells

We have developed the first safety test specifically for iPS cells. This is a significant step in improving the quality of iPS cells and identifying unwanted cells that can form tumours.

The test uses laser technology to identify proteins found on the surface of the cells. Based on the presence or absence of specific proteins the cells are then separated and monitored. Unsafe stem cell lines are easily identified because they form recognisable clusters of cells and the safe ones don't.

Using this test method, our researchers have shown that certain ways of making iPS cells carry more risks.

When the standard technique is used, which relies on viruses to permanently change the DNA of a cell, unwanted tumours are more likely to form. In comparison, cells made using methods which do not alter cell DNA, do not form tumours.

The results

Improving quality control around the globe

The new test method has helped raise the awareness and importance of stem cell safety, and is expected to lead to improvements in quality control globally.

Professor Martin Pera, Program Leader of Stem Cells Australia, said: "Although cell transplantation therapies based on iPS cells are being fast-tracked for testing in humans, there is still much debate in the scientific community over the potential hazards of this new technology."

"This important study provides a simple and powerful technique for assessing how safe stem cell lines are for use in patients," he said.

Dr Andrew Laslett: Using technology developed at CSIRO we've been able to show that we can identify unsafe IPS cells. That's important because IPS cells have a real potential for being used in drug discovery and for potentially being used in cell therapy to treat a range of human diseases and injuries.

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So the test shows that some IPS cell lines made using viruses actually are able to re-form stem cells.

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Now this is a real danger in and we've shown that when we put these cells into animals that they are capable of forming tumours known as teratomas. So what this test shows is that these cell lines made using viruses are both unstable and unsafe for human use.

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One of the other reasons this study is important is because IPS technology is just starting to make the switch from a research to a potential clinical application.

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And as such there are regulations that cover cell therapy in general but there's no real safety tests available that are specific for IPS cells or induced very potent stem cells.

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What we hope the publication of this test will do is to show people that not all stem cells are safe, we need to be really careful when we're thinking about putting cells made from stem cells into people. And there's also a large number of quasi legal stem cell companies in multiple countries around the world that are using stem cells to treat people.

People need to be very careful about that because our test shows that the easiest and simplest ways to make stem cells known as IPS cells is in fact quite dangerous for human health.